Method of forming a branching to a pipe, and junction in a pipe

ABSTRACT

The present invention relates to a junction in a pipe for connecting the pipe ( 1 ) into fluid communication with a fluid-carrying component ( 18 ), the junction comprising an opening ( 2 ) provided in the wall of the pipe and a connecting part ( 3 ) comprising a tube-clamp-like joint ( 3 ) comprising a first part ( 4 ) and a second part, which can be tightened against the first part by means of tightening means ( 6 ) and which comprises a narower first portion ( 10 ) and a broader second portion ( 11 ), whereby the narrower portion is positioned in the opening ( 2 ) and the broader portion outside the pipe ( 1 ). The invention also relates to a method of forming to the wall of a pipe a branching for receiving a fluid-carrying component.

BACKGROUND OF THE INVENTION

The invention relates to a method of forming to the wall of a pipe abranching for receiving a fluid-carrying component, the methodcomprising processing into the pipe wall a cylindrical opening having asmaller diameter than the pipe, thereafter fastening the component tothe pipe at the opening such that the pipe and the component are influid communication, the method comprising arranging around the pipe atube-clamp-like joint comprising a first part and a second part, whichcan be tightened against the first part by means of tightening means andwhich comprises a conduit and a bushing part and a narrower firstportion and a broader second portion, and the narrower portion isinserted in the hole, and the second part it tightened against the pipewall and the component can be fastened in the conduit.

The invention also relates to a junction in a pipe for connecting thepipe into fluid communication with a fluid-carrying component, thejunction comprising an opening provided in the wall of the pipe and aconnecting part between the pipe and the component, the connecting partcomprising a tube-clamp-like joint comprising a first part and a secondpart, which can be tightened against the first part by means oftightening means and which comprises a bushing part and a narrower firstportion and a broader second portion, whereby the narrower portion ispositioned in the opening and is surrounded by the walls of the hole andthe broader portion is positioned outside the pipe, the narrower portioncomprises a first projected surface which is smaller than a secondprojected surface in the broader portion of the second part, theprojected surfaces being directed away from one another, the firstprojected surface being arranged to exert a first force directed at thenarrower portion during fluid pressure in the pipe the first forcetending to push away the narrower portion from the hole and the secondprojected surface being arranged to exert a force directed at thebroader portion during the same fluid pressure, this force tending topush the narrower portion towards the pipe in such a manner that a forceacts so as to wedge the narrower portion into the hole.

Fluid communication refers herein to the ability of fluid to stream inthe junction.

The invention is particularly well applicable to metal pipes, althoughother pipe materials are also feasible.

There are many ways of connecting a fluid-carrying component, e.g. apipe or a pipe part, to the wall of another pipe. A common way is to usein the junction a T coupling implemented by a tee. However, a T couplingsuffers from drawbacks. One drawback is that the junction istime-consuming, because the pipe has to be cut off to the right lengthto allow room for the tee, and the tee then has to be connected in afluid-tight manner at the three free ends thereof. If the junction isimplemented by welding, which is often the case in high pressure pipes,the junction requires extensive welding, which may impair thecharacteristics of the pipe material, even though heat treatmentoptionally follows the welding. Another drawback in the use of a Tcoupling is that the tee may be, in spite of a relatively small pipedimension of 38 mm, for example, extremely costly, particularly in highpressure applications.

When a spray head or a sprinkler operated by a pressure exceeding 16bar, e.g. 25 to 300 bar, is to be connected to a pipe, the junction iscostly to implement by known methods and known components, becauseespecially high safety and tightness requirements are made on a highlyloaded junction.

It is known through GB 2 254 119 and GB 2 125 920, for example, toconnect components to a pipe by processing an opening into the wall ofthe pipe. Junctions implemented in this way are tightened by means ofelastic seals. Elastic seals are always complicated in high pressureapplications, because they easily yield to pressure, easily causingleakage. In the known construction according to GB 2 125 920, a tongue18 remains in a certain portion and prevents fluid from flowing freelyto and from the pipe. The higher the pressure of the fluid in the pipe,the stronger is the resistance provided by the tongue.

BRIEF DESCRIPTION OF THE INVENTION

For the purpose of eliminating the above drawbacks, the method of theinvention is characterized by

processing a cylindrical hole having a diameter smaller than thediameter of the pipe, the hole forming said opening, thereupon

tightening the second part, so that its narrower portion plasticallydeforms the walls of the hole so that these walls encircle the narrowerportion fluid tight.

According to a preferred embodiment, which is especially suitable forhigh pressure connections, fluid is introduced into the pipe under highpressure which acts on a first projected surface and a second projectedsurface that is larger than the first projected surface, the pressure onthe first surface producing a first force that tends to push away thenarrower portion from the hole and the pressure on the second surfaceproducing another force whose direction is opposite to the first forceand which is stronger than the first force and which pushes the narrowerportion into the hole for deformation of the walls of the hole. The useof a high pressure, e.g. 100 to 300 bar, results in a very firmconnection. A lower pressure in excess of 16 bar, which is typicallyacting when the pipe is in use, keeps the junction tight. Thus apressure in the pipe tends to close or seal, not open, the junction.

The preferred embodiments of the method of the invention are disclosedin the attached claims 2 to 5.

The junction of the invention is characterized in that the walls of thehole are plastically deformed, and encircle the narrower portion fluidtight. The construction is particularly suitable for high pressureapplications. The use of an insert which is small in relation to thetube clamp and provided with a conical surface for resting against theedge of the hole results in an economic solution allowing the connectionof different components to the pipe. Such an insert is easy to make incomparison to a solution in which the whole of the second part of thejoint would be produced as an uniform, integrated part. An integratedpart would be very difficult, if not impossible to make by machining,and would consequently have to be cast.

The major advantages of the method of the invention are that thebranching can be produced simply, rapidly and economically withoutelastic seals and that the result is a branching which tightly andreliably connects the fluid-carrying component in spite of applicationof high pressure.

The major advantages of the junction are that it is tight even when highpressure is applied, that it is reliable and can be producedeconomically.

BRIEF DESCRIPTION OF THE FIGURES

In the following the invention will be described by means of twoembodiments with reference to the attached drawing, in which

FIGS. 1 to 6 illustrate a first embodiment of the method of making abranching according to the invention,

FIGS. 7 and 8 show the results of FIGS. 1 to 6,

FIGS. 9 and 10 illustrate a second embodiment of the method of making abranching according to the invention, and

FIGS. 11 and 12 show the results of FIGS. 9 and 10.

DETAILED DESCRIPTION OF THE INVENTION

Upon making a branching according to the invention, a hole is first madein a pipe 1 which is to be provided with the branching, see FIGS. 1 and2 which illustrate a manner of processing a hole 2 in the pipe. The pipeis a metal pipe 1 and the hole 2 is made with an ordinary drill bit,which upon drilling is supported by a tube-clamp-like joint 3 whichencircles the pipe 1. The joint 3 comprises a lower part 4 and an upperpart 5 which are tightened against one another by screws 6 or bolts. Theupper part 5 is provided with a bushing part 7 which guides the drillbit during drilling. Alternatively, the hole 2 can be drilled freehand,i.e. without a tube clamp 3, but the joint is preferable as itsignificantly facilitates the drilling and ensures that the hole 2 islocated exactly at the desired point. Instead of drilling, it isfeasible that the hole is made by another manner.

After the hole 2 has been drilled, the joint 3 is opened and the bushingpart 7 is replaced by another bushing part 8, see FIGS. 3 and 4. FIG. 4shows an explosion view of FIG. 3 seen from the side. In FIG. 4,reference 1 denotes a long pipe, which is usually employed in utilizingthe invention. An insert 9 is placed between the upper and lower partsof the tube clamp. The insert 9 is provided with an at least mainlycylindrical narrower portion 10 and a cylindrical broader portion 11, aconical surface 12 forming between said portions. The diameter of thenarrower portion 10 corresponds mainly to the diameter of the hole 2. Aconduit 13 extends through the insert 9.

The bushing part 8 comprises a recess 14 for receiving the broader part11 of the insert (cf. FIG. 5). The recess 14 comprises an abut surface15 against which the upper portion 11 of the insert 9 is arranged torest. Thus the bushing part 8 comprises a conduit 25 whose diameter issmaller than that of the recess 14.

The lower end of the bushing part 8 is provided with a flange-likeportion 30 which is arranged under a flange-like clamp frame 31 in theupper part 5 of the joint such that a tightening surface 32 is providedbetween the flange-like portion 30 and the flange-like clamp frame 31.

The upper part 5 of the joint is tightened against the lower part 4 ofthe joint by means of the screws 6, see FIGS. 5 and 6. FIG. 6 is a sideview of FIG. 5. As the screws 6 are tightened, the bushing part 8 andthe insert 9 bear down on the pipe 1. First, a gap 16 is formed betweenthe pipe 1 and the upper part 5 of the joint 3 as a result of theconical part 12 of the insert resting against the upper edge 17 of thehole. By further tightening of the screws 6 of the joint, the conicalpart of the insert penetrates to some degree into the hole 2 and deformsthe area closest to the hole, the upper edge 17 of the hole inparticular.

FIGS. 7 and 8 show a completed junction in the form of a T coupling withthe edge 17 of the hole deformed. The figures show how a pipe 18 havinga smaller diameter than the pipe 1 is connected to the latter pipe.Instead of a straight pipe, a pipe bow or another pipe component cannaturally be used. The pipe 18 is located in a recess 19 in the bushingpart 8 and is fastened to the bushing part by a cap 20 having a hole forthe pipe and threads 21 that operate together with threads 22 in thebushing part. The space under the cap 20 and the recess 19 containmaterial 23 that cuts into the pipe 18 and provides a tight jointbetween the pipe 18 and the bushing part 8 and prevents the pipe 18 frombeing axially drawn away from the recess 14. In stead of such a cuttingcoupling, it is feasible, mainly in exceptional cases, that the pipe 18is fastened to the bushing part 8 by welding. The insert 9 comprises inits broader portion an O seal 24 which prevents fluid from passingbetween the insert and the wall of the recess 14. A second seal 26 isarranged in the area of the conical surface of the insert. This seal isnot necessary, but serves as extra security to prevent fluid in the pipe1 from passing outside the bushing part 8 in an area between the bushingpart and the upper part 5 of the tube clamp.

The junction in FIG. 7 is particularly advantageous because the narrowerportion 10 of the insert 9 comprises a surface 27 which is under fluidpressure and smaller than a surface 28 in its upper portion 11 underfluid pressure. The surface 28 is under fluid pressure because theconduit 13 of the insert has a smaller diameter than the conduit 25 ofthe bushing part 8. Because the surface 28 is larger than the surface27, a pressure in the pipes 1, 18 produces a force which tends to pushthe insert 9 towards the pipe 1. When a pressure exceeding 25 bar, e.g.100 to 300 bar, is used, the insert 9 is pushed forcefully against thepipe 1 such that the pipe material is deformed plastically in the areaof the hole 2. The insert 9 can be heavily wedged into the pipe 1 byapplication of such a pressure. A pressure range between 25 and 100 baris also feasible, but in that case the force wedging the insert isnaturally not that effective. To guarantee the rigidity of the pipejoint under all circumstances, the screws 6 are tightened after thepressure load. The surfaces 27 and 28 are parallel, but this is notnecessary because to achieve a force wedging the insert 9 into the pipe,it is vital that the insert comprises a first projected surface which islarger than a second projected surface, the projected surface beingopposite in direction and the first projected surface being arrangedunder fluid pressure in the pipe 1 to push in the insert 9 against thepipe 1. In principle, the projected surfaces can be of any shape.

FIGS. 9 to 12 show another embodiment and another application of thejunction. In stead of a pipe, a spray head 18′ or a sprinkler isconnected to the pipe 1′ in the figures. FIGS. 9 and 10 show anexplosion view of FIGS. 3 and 4; FIGS. 11 and 12 show the completedjunction. Even this embodiment employs a tube-clamp-like joint 3′ and aninsert 9′ like the one in FIGS. 3 to 8. The joint 3′ differs from thejoint 3 in FIGS. 3 to 8 in that the upper part of the joint is composedof two parts 5 a′, 5 b′. The reason for the use of two parts 5 a′, 5 b′is that the bushing part 8′ for receiving the spray head has such alarge outer diameter that it cannot pass through the flange-likeperiphery of the inner diameter D of the part 5 shown in FIG. 3. Inother words, the installation of a projection 37′ in the bushing part 8′against the inner diameter of the flange-like periphery from the lowerside would become impossible. The bushing part 8′ cannot be installedfrom the upper side either because the flange-like portion 30′ has alarger diameter than the inner diameter of the flange-like periphery,which is also true of FIGS. 3 to 8. However, the parts 5 a′ and 5 b′enable simple mounting.

The bushing part 9′ comprises a recess 19′ for receiving the spray head18′. The recess 19′ is provided with threads 22′ for co-operation withcorresponding threads 21′ in the body 36′ of the spray head.

The parts 5 a′ and 5 b′ are tightened against the pipe 1′ with screws,as in FIGS. 5 and 6.

FIGS. 11 and 12 show the completed junction, in which the insert 9′ hasplastically deformed the material around the hole 2′.

The insert 9, 9′ is of a corrosion resistant metal, while the rest ofthe tube-clamp-like joint 3, 3′ is of a metal having lower corrosionresistance. This provides an economical junction.

In the above the invention has been described with reference to only twoembodiments and it should therefore be pointed out that the details ofthe invention may vary in a variety of ways within the scope of theattached claims. Accordingly, instead of a pipe or a spray head, anyfluid-carrying component may be employed. A separate insert 9, 9′ is notnecessary in all applications, but it is to be preferred. The formationof the bushing 8, 8′ may vary.

What is claimed is:
 1. In a method of forming to the wall of a pipe (1,1′) a branching for receiving a fluid-carrying component (18, 18′), themethod comprising processing into the pipe wall a cylindrical hole (2,2′) having at least one wall defining a smaller diameter than a diameterof the pipe, arranging around the pipe (1, 1′) a tube-clamp-like joint(3, 3′) comprising a first part (4, 4′) and a second part (5, 5 a′ 5 b′)for tightening against the pipe wall and first part by, tightening means(6, 6′), the second part comprising a conduit (25) with a bushing (8, 9,8′,9′), the bushing having a narrower first portion (10, 10′) forinsertion into the hole (2, 2′) and a broader second portion (11, 11′),inserting the narrower portion (10, 10′) into the hole (2, 2′), andtightening the second part (5, 5 a′, 5 b′) is tightened against the pipewall and the component (18, 18′) fastened in fluid communication withthe conduit (25), the improvement wherein the second part (5, 5 a′, 5b′) is tightened so that the narrower portion of the bushing (10, 10′)plastically deforms the wall of the hole (2, 2′) and the wall of thehole encircles the narrower portion fluid tight.
 2. A method as claimedin claim 1, characterized by introducing into the pipe (1, 1′) a fluidunder high pressure, the pressure acting on a first projected surface(27, 27′) and a second projected surface (28, 28′) which is larger thanthe first projected surface, the pressure on the first surface producinga first force which tends to push away the narrower portion (10, 10′)from the hole (2, 2′) and the pressure on the second surface producing asecond force, which is opposite to the first force and stronger than thefirst force and which pushes the narrower portion into the hole anddeforms the wall of the hole.
 3. A method as claimed in claim 1,characterized by introducing the fluid into the pipe (1, 1′) by apressure of 25 to 300 bar.
 4. A method as claimed in claim 1 forproviding a branching in the form of a branch in the form of a Tcoupling in the pipe, characterized by using another pipe (18) as thecomponent.
 5. A method as claimed in claim 1, characterized by using apray head (18′) as the component.
 6. A junction in a pipe for connectingthe pipe (1, 1′) into fluid communication with a fluid-carryingcomponent (18, 18′), the junction comprising a hole (2, 2′) provided inthe wall of the pipe and a connecting part (3, 3′) between the pipe andthe component, the connecting part comprising a tube-clamp-like joint(3, 3′) having a first part (4, 4′) and a second part (5 a′, 5 b′),which can be tightened against the first part by means of tighteningmeans (6, 6′) and which comprises a bushing part (8, 9, 8′, 9′) and anarrower first portion (10, 10′) and a broader second portion (11, 11′),whereby the narrower portion is positioned in the opening (2, 2′) and issurrounded by the walls of the hole and the broader portion ispositioned outside the pipe (1, 1′), the narrower portion (10, 10′)comprises a first projected surface (27, 27′) which is smaller than asecond projected surface (28, 28′) in the broader portion (11, 11′) ofthe second part, the projected surfaces being directed away from oneanother, the first projected surface being arranged to exert a firstforce directed at the narrower portion during fluid pressure in the pipe(1, 1′), the first force tending to push away the narrower portion fromthe hole (2, 2′) and the second projected surface being arranged toexert a force directed at the broader portion during the same fluidpressure, this force tending to push the narrower portion towards thepipe in such a manner that a force acts so as to wedge the narrowerportion into the hole, characterized in that the walls of the hole (2,2′) are plastically deformed, and encircle the narrower portion (10,10′) fluidum-tight.
 7. A junction as claimed in claim 6, characterizedby the second part comprising an insert (9, 9′) having a conical surfacefor resting against the edge of the hole (2, 2′).
 8. A junction asclaimed in claim 7, characterized by the insert (9, 9′) being of acorrosion resistant metal, while the rest of the tube-clamp-like joint(3, 3′) is of a metal having lower corrosion resistance.
 9. A junctionas claimed in claim 7, characterized by the insert comprising saidnarrow portion (10, 10′) which is insertable into the hole (2, 2′). 10.A junction as claimed in claim 9, characterized by the insert (9, 9′)comprising said broader portion (11, 11′) provided in the bushing part(8, 8′) in the second part (5, 5 a′, 5 b′).
 11. A junction as claimed inclaim 10, characterized by a seal (24, 24′) being arranged around thebroader portion (11, 11′) for sealing the insert (9, 9′) against thebushing part (8, 8′).
 12. A junction as claimed in claim 10,characterized by the component being a second pipe (18) and the junctionbeing a T coupling, whereby the bushing part (8) comprises a recess (19)for receiving the second pipe, and threads (22) for receiving a cap (20)which is provided with holes for the second pipe and threads (21)corresponding to the threads of the bushing part, by means of whichthreads (21, 22) the second pipe is fastened to the bushing part as acutting coupling.
 13. A junction as claimed in claim 10, characterizedby the component being a spray head (18′), the bushing part (8′)comprising a recess (19) for receiving the body of the spray head, andthreads (22′) for receiving threads (21′) in the body (36′) of the sprayhead, by means of which threads in the body the spray head is fastenedto the bushing part (8′).
 14. A junction as claimed in claim 13,characterized by the second part of the joint comprising two parts (5 a′and 5 b′) which comprise a flange-like clamp frame arranged to beinserted into a projection (37′) in the bushing part (8′) whose outerdiameter in the area of the recess (19′) is larger than the innerdiameter of the flange-like clamp periphery.